Question

Which of the following statements is CORRECT?

a
The initiator tRNA (bound to small ribosomal subunit) is located in the A site.
b
The start codon is AUG.
c
Elongation of translation occurs when an incoming amino-acyl-tRNA comes to the P site.
d
The activity of the amino-acyl-transferase is required to mediate peptide bond formation.
e
Termination of translation occurs when the tRNA recognizes the stop codon in the A site.

Answer 1

The correct statement among the given options is that the start codon is AUG. The initiator tRNA binds to the P site, not the A site, during initiation, and peptide bond formation during elongation involves a ribozyme, not an amino-acyl-transferase.

Step-by-step explanation:

The correct statement is: The start codon is AUG.

During the initiation phase of translation, the initiator tRNA carrying methionine binds to the P site of the ribosome where it pairs with the AUG start codon. Elongation involves charging tRNAs entering the A site, not the P site, and peptide bonds forming between adjacent amino acids. This bond formation is not mediated by amino-acyl-transferase but rather by the ribozyme peptidyl transferase. Termination of translation indeed occurs when a stop codon is encountered in the A site, which is recognized by release factors, not by a tRNA.